Design and synthesis of azaisoflavone analogs as phytoestrogen mimetics

European Journal of Medicinal Chemistry 85 (2014) 107e118

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European Journal of Medicinal Chemistry journal homepage: http://www.elsevier.com/locate/ejmech

Original article

Design and synthesis of azaisoflavone analogs as phytoestrogen mimetics Hyo Jin Gim a, 1, Hua Li a, 1, So Ra Jung a, Yong Joo Park b, Jae-Ha Ryu a, Kyu Hyuck Chung b, Raok Jeon a, * a

Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women's University, 52 Hyochangwon-Gil, Yongsan-Ku, Seoul 140-742, Republic of Korea School of Pharmacy, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, Republic of Korea

b

a r t i c l e i n f o

a b s t r a c t

Article history: Received 28 September 2013 Received in revised form 30 June 2014 Accepted 2 July 2014 Available online 15 July 2014

A series of azaisoflavone analogs were designed and synthesized and their transactivation activities and binding affinities for ERa and ERb were investigated. Among these compounds, 2b and 3a were the most potent with 6.5 and 1.1 mM of EC50, respectively. Molecular modeling study showed putative binding modes of the compound 3a in the active site of ERa and ERb, which were similar with that of genistein and provided insight of the effect of N-alkyl substitution of azaisoflavones on ERb activity. Also, a biphasic effect of azaisoflavone analogs on MCF-7 cell growth depending on their concentrations was investigated. © 2014 Elsevier Masson SAS. All rights reserved.

Keywords: Estrogen receptor ER agonist Azaisoflavones Proliferation

1. Introduction Estrogen receptors (ERs), a member of the steroid nuclear hormone receptor family, are ligand-activated transcription factor which play a crucial role in the development, maintenance, and function of the female reproductive system as well as other tissues such as colon, prostate, bone, cardiovascular system and central nervous systems [1]. There are two isoforms, ERa and ERb. ERa is expressed in nearly all tissues whereas ERb is mainly expressed in the ovaries, uterus and oviduct of the female reproductive tract but not in breast tissue [2]. ERa and ERb have different biological functions including a tissue-specific regulation as well as their different gene expression patterns [3]. The hormone 17b-estradiol (E2) binds to ligand binding domain (LBD) of ERs, enters the nucleus of the cell, and regulates the target gene expression related to proliferation and differentiation of the cell by recruiting a various co-regulators. A deficiency of estrogen is associated with hot flashes, sweating, heart attacks and bone loss and hormone replacement therapy (HRT) is a medical treatment for older postmenopausal women in order to reduce these symptoms

* Corresponding author. E-mail address: [email protected] (R. Jeon). 1 These authors contributed equally to this work. http://dx.doi.org/10.1016/j.ejmech.2014.07.030 0223-5234/© 2014 Elsevier Masson SAS. All rights reserved.

[4]. However, Women's Health Initiative (WHI) study showed beneficial effects of estrogen could increase risk of certain cancers such as breast [5]. Selective ER modulators (SERMs) are therapeutic agents for treating osteoporosis and breast cancer by modulating both ERs [6]. Tamoxifen, the first clinically relevant SERM, antagonizes the ER in breast tissue via active metabolite, hydroxytamoxifen and inhibits estrogenic effects such as proliferation of cancer cell [7]. Recently, a number of researches have been demonstrated ERa is more active in driving breast cancer cell proliferation than ERb [8]. Meanwhile, it has been demonstrated that ERb has antiproliferative effect in breast cancer cells [9] and preventive effects for prostate adenocarcinoma [10] and also modulates the immune response [11]. Therefore, discovery of selective ERb agonists may provide high potential to develop therapeutic agents for the various diseases such as breast cancer, prostate cancer, endometriosis, and inflammation. Recently, non-steroidal selective ERb agonists SERBA-1, ERB-041 and WAY-202196 have been reported their antiinflammatory activities and estrogenic activities (Fig. 1). Phytoesterogens, naturally occurring estrogenic plant compounds, have been considered as an alternative method of menopause treatment. Among them, isoflavones are the well-known ER agonistic phytoestrogens and exhibit a number of biological properties including the prevention of cancers [12], coronary heart diseases [13], and osteoporosis [14]. Genistein is one of the potent

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Fig. 1. Structures of ER modulators.

phytoestrogenic isoflavone, reveals 10e40 fold greater affinity for ERb than for ERa [15], and inhibits cell proliferation in various breast cancer cell lines including MCF-7, T47D, BT20, MD-MBA-231, and SKBR3 [16]. The biphasic effect of genistein on cell growth has been reported in several studies in which genistein increased the MCF-7 cell growth at low concentrations but inhibited at higher concentrations [16a,17]. ERa and ERb are similar in sequence with 58% identity and both ligand biding domains (LBDs) are nearly conserved differing by only two amino acids; Leu384 and Met421 in ERa are replaced by Met336 and Ile373 in ERb, respectively (Fig. 2) [18]. The hydroxy groups in both ends of E2 and genistein essentially interact with key residues such as Glu353, Arg394 and His524 of ERa by hydrogen bonding within 2e3 Å (Glu305, Arg346 and His475 of ERb). Their different residues Leu384/Met336 are positioned above the C-ring of genistein in the distance of 4e5 Å, and Met421/Ile373 are located below the A-ring near C-5 hydroxy group of genistein. These two pairs of amino acids within the LBD of ERa and ERb make slight differences and mainly contribute to ligand selectivity [9c,19] (Fig. 3). Regarding the previous findings, we became interested in modifying C-ring of isoflavone to identify a novel selective ER agonist. In this point of view, a previously reported compound azaisoflavone became the object of our attention. In fact, azaisoflavones were originally derived from isoflavone scaffold and designed as an iNOS inhibitor since inhibitory activity of several naturally occurring isoflavone for NO production was reported [20]. We supposed that the azaisoflavone analogs could function as phytoestrogens. Furthermore, N-substitution of azaisoflavone ring may give selectivity for ligand binding domains of ERa and ERb. Herein we report synthesis of azaisoflavone analogs and their ERa/b transactivation activities. Structure activity relationship study was focused on the influence of phenolic OH of A and B-ring and Nsubstitution of C-ring of azaisoflavones. The effect of azaisoflevones on MCF-7 cell proliferation was also evaluated. 2. Chemistry Synthetic routes for the preparation of azaisoflavones 1a-3d are outlined in Scheme 1. Aniline or methoxyaniline was acylated with acetonitrile in the presence of boron trichloride and aluminum trichloride by FriedeleCraft’s reaction. Condensation of the resulting ketones 4ae4c with p-anisaldehyde resulted in 2’-

aminochalcones 5ae5c which were followed by N-acetylation to afford 2’-acetamidochalcones 6ae6c. Rearrangement of 2’-acetamidochalcone 6ae6c in the presence of thallium nitrate and trimethyl orthoformate gave b-ketoacetal 7ae7c which were subsequently cyclized under acidic condition to yield quinolones 8ae10a. The resulting quinolones 8ae10a were alkylated with various alkyl halides in the presence of base to afford N-alkylated quinolones 8be10d. The final hydroxyquinolones 1ae3d were obtained by deprotection of methoxyquinolones 8ae10d under HBr and acetic acid conditions, respectively. 3. Results and discussion 3.1. ER transactivation activity and binding affinities ER agonist activities of the prepared compounds were evaluated by in vitro transient transactivation assay and described in Table 1. The efficacy of the tested compounds was compared to the reference compounds E2 and genistein. At first, an importance of phenolic OH on A and B-ring of azaisoflavones was investigated. Mono-hydroxy analogs 1aed, dihydroxy of daidzein analogs 2aec and tri-hydroxy of genistein analogs 3aec were compared with the corresponding methoxy compounds 8a, 9aec and 10aec, respectively. All methoxy compounds showed lower activities than the respective hydroxy compounds, and mono-hydroxy analog 1a was less active than daidzein analog 2a and genistein analog 3a as expected. When the oxygen of genistein was simply replaced with nitrogen as depicted in compound 3a, both ER activities were dropped, whereas the selectivity for ERb was increased. Genistein type analog 3a showed the highest ERb activity with 2.9 fold selectivity over ERa. Effect of N-alkyl substituent of azaisoflavone on ER activity was evaluated. In the case of mono-hydroxy compounds 1aed, only Npropylated compound 1d showed increased ERa and b activity than the parent compound 1a while N-methyl or ethyl substitution vanished activity. In the daidzein analogs 2aef, introduction of alkyl substituent at nitrogen of C-ring enhanced ERb activity and selectivity. Especially, N-methyl substituted compound 2b showed promising ERb activity with the highest ERb selectivity at the ratio of 6.4:1. When the size of substituent was increased, the ERb activity was decreased. In the genistein analogs 3aec, N-alkyl substitution lowered ERb activity and selectivity. In contrast, N-alkyl

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Fig. 2. Differences between the crystal structures of ERa and ERb complexed with genistein. Two different colors represented complexed structures of genistein with LBDs of ERa (megenta) and ERb (green) (PDB ID: ERa-1X7R and ERb-1X7J). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

substitutions have relatively weak influence in the ERa activity of both daidzein and genistein analogs. Among these compounds, Nmethylated daidzein analog 2b and non-alkylated genistein analog 3a were the most potent ERb agonists showing 6.5 mM and 1.1 mM of EC50 value, respectively. The binding affinities of azaisoflavones for ERa and ERb were determined by a radiometric competitive binding assay and depicted in Table 1. Most of the azaisoflavone analogs revealed rare ERa binding affinity except tri-hydroxy of genistein analogs. Genistein analogs 3aec showed remarkable ERb binding affinity along with relatively lower ERa binding affinity. Introduction and lengthening of N-alkyl substituents of genistein analogs increased both ERa and b binding affinities although selectivity was reversely lowered. Thus, non-substituted genistein analog 3a showed the most selective binding affinity for ERb. IC50 values of genistein analogs were determined; 3a (74.5 mM for ERa, 4.2 mM for ERb), 3b (35.6 mM for ERa, 0.72 mM for ERb), 3c (18.4 mM for ERa, 0.10 mM for ERb), and 3d (16.6 mM for ERa, 0.15 mM for ERb). Di-hydroxy of daidzein analogs showed moderate binding affinity for ERb with no affinity for ERa, and N-alkyl substitution slightly enhanced ERb binding affinity. Interestingly, these results of ERb binding affinity were not correlated with transactivation activity mentioned above. There is a quite discrepancy between transactivation activity and binding affinity and it may be ascribed to the causes that the receptoreligand complex is only present in the binding assays, whereas various interactions with the many coregulators are present in the cellular transcription assays [21]. These interactions with coregulators can modulate the transcriptional activities of ligand.

Fig. 3. Representative structure of azaisoflavone analogs.

3.2. Docking analysis To compare binding modes between known isoflavone and azaisoflavone and to explain the effect of N-alkyl group on the ERa/ b selectivity, A docking analysis of azaisoflavones 2aef and 3aed were carried out using Surflex Dock interfaced with SYBYL-X version 2.0. Crystal structures of hERa and hERb in complex with genistein (PDB code: ERa
1X7R, ERb
1X7J) were employed for the docking study and internal default parameters of Surflex Dock were used for all the variables. We investigated closely binding modes of azaisoflavones at the active site of ERa/b in comparison with that of genistein. Herein we took note of two points. First, the distance between centroid C-ring of genistein and Met336 in ERb is closer than that of genistein and Leu384 in ERa. It is known to causes relatively stronger Metaromatic interaction in ERb than Leu-aromatic interaction in ERa, so it is consisted with the observed selectivity of genistein for ERb over ERa. Also, it has been reported genistein C-5 hydroxy group is repulsive to the Met421 sulfur atom in ERa, but not to Ile373 in ERb [22]. A number of ERb selective agonists were reported [19]. Among them, benzoxazole analog ERB-041 provides good example for the role of Met421 in ERa and Ile373 in ERb to distinguish ERa from ERb. ERB-041 has 200 folds selectivity for ERb and was proposed that the vinyl group of benzoxazole ring made steric clash with Met421 in ERa, which is relatively longer than Ile373 in ERb. In contrast, this vinyl substituent appropriately positioned near Ile373 in ERb, and even forming an additional hydrophobic interaction [23]. Azaisoflavone 3a showed a similar binding mode with genistein whose hydroxyl groups of A and B-ring interact with the critical residues including His, Glu, Arg, and water molecule within appropriate distance in the active site of both ERs as shown in Fig. 4. Regarding the previous report, we also assume favorable Met336aromatic interaction of 3a in ERb. In fact, C4 atom of 3a located at a closer distance of 3.744Å from Sd of Met336 in ERb, on the other hand, 3.886 Å from Cd2 of Leu384 in ERa. Additional H-bonding interaction was observed between C-7 hydroxy group of compound 3a and Gly472 in ERb. Fig. 5 exhibited binding modes of N-alkylated daidzein analogs at the active site of ERa and b. N-alkylated genistein analogs showed relatively low docking scores compared with N-alkyalted

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Scheme 1. Synthesis of azaisoflavone analogs. Reaction conditions: a) CH3CN, BCl3, AlCl3, dichloroethane, 80  C, 20 h; b) p-anisaldehyde, NaOH, EtOH, rt, 10 h; c) Ac2O, pyridine, rt, 3 h; d) thallium(III)nitrate, HC(OCH3)3, rt, 4 h; e) HCl, EtOH, reflux, 2 h; f) R3-X, NaH, DMF, rt, 3e12 h; g) HBr, AcOH, 120  C, 3 days.

daidzein analogs in accordance with transactivation activities. In the case of ERa, when alkyl substituents were introduced at the nitrogen of daidzein analogs, they occupied an empty space near Leu384 which might be more acceptable than longer Met336 for these alkyl groups. On the other hand, binding modes in ERb LBD were quite different with those in ERa. The daidzein analogs 2bed were flipped over retaining their key H-bonding interactions with Glu305, Arg346, His475, and water molecule. Methyl, ethyl and propyl groups were positioned near Ile373 instead of Met336 as shown in Fig. 5. The docking scores of 2bed decreased with lengthened alkyl substituents showing Me (6.8615), Et (6.8290), and Pr (6.6300). Methyl group of azaisoflavone 2b seemed to be the most suitable substituent for the cavity near Ile373. Taken together, docking result gave an account of the transactivation activity and selectivity of the discussed compounds. 3.3. Effects of MCF-7 cell growth Some phytoestrogens are known to modulate survival and death of breast cancer cell in an ER-dependent or -independent manner [24]. Interestingly, genistein and daidzein have been found to stimulate breast cancer cell growth in vitro and in vivo studies at low concentrations (0.1e10 mM) while they inhibit the cell proliferation at high concentrations (20e100 mM) [17,25]. However, the mechanism of the biphasic action of genistein on the growth of breast cancer cells is not fully understood yet. The proliferative and/or anti-proliferative activity of mostly ER active azaisoflavone analogs on MCF-7 cell was also evaluated.

MCF-7 (ATCC HTB-22) and CV-1 (ATCC CCL-7) cells were maintained at 37  C in a humidified atmosphere of 5% CO2 in DMEM supplemented with 10% fetal bovine serum (FBS; GE Healthcare). The cells were cultured in phenol red-free DMEM containing 5% charcoal-dextran stripped FBS (CD-FBS) for 3 days to eliminate any estrogenic source before treatment of samples. Effect of azaisoflavones on cell growth was not correspondingly related to the ER activity. Among tested compounds, azaisoflavones 1d, 2c, 2d, 3a, 3b and 3c showed biphasic effects with stimulation of cell growth at low concentrations and inhibition at high concentrations as genistein did (Fig. 6). Meanwhile, compounds 2e, 2f and 3d were only observed inhibitory activity at the given doses. 4. Conclusion In summary, we have designed and synthesized a series of azaisoflavones based on phytoestrogenic isoflavone scaffold and evaluated their estrogenic activity and binding affinities in the LBD of ERa and b. We found that several azaisoflavone analogs displayed promising estrogenic activity and subtype selectivity. Also, most of the azaisoflavone analogs were found to modulate the proliferation of MCF-7 breast cancer cells in a dose dependent manner. SAR study indicated that presence of hydroxy group is critical for the ER activity while the potency and selectivity of the compounds were highly influenced within a very narrow structural change. Interestingly, introduction of optimal length of N-alkyl substituent in the daidzein anlalogs increased ER activity, meanwhile genistein analogs lowered ERb activity with N-substitution. Molecular modeling

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Table 1 In vitro functional transactivation activities and competitive binding affinities of azaisoflavones on human ERa/b.

Compds

R1

R2

R3

R4

ER transactivation activity % max (20 mM)a

Genistein 1a 1b 1c 1d 2a 2b 2c 2d 2e 2f 3a 3b 3c 3d 8a 9a 9b 9c 10a 10b 10c E2d

OH H H H H H H H H H H OH OH OH OH H H H H OMe OMe OMe

OH H H H H OH OH OH OH OH OH OH OH OH OH H OMe OMe OMe OMe OMe OMe

OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH OMe OMe OMe OMe OMe OMe OMe

e H Me Et Pr H Me Et Pr i-pentyl Bn H Me Et Pr H H Me Et H Me Et

ERa

ERb

172.8 NAc NA NA 79.0 24.5 16.1 33.1 42.3 13.0 31.7 46.2 50.4 60.5 56.9 NA NA NA NA 10.1 NA NA 100

232.8 19.6 NA NA 42.4 31.9 102.1 95.4 67.0 44.8 33.1 132.1 63.2 47.2 16.7 10.1 16.2 10.3 NA 10.9 NA 13.2 100

ER binding affinity

b/a ratio

% max (20 mM)b ERa

ERb

1.3

93.4 NA NA NA NA NA NA NA NA NA NA 6.9 35.6 57.0 78.5 NA NA NA NA NA NA NA 100

95.1 10.7 18.4 18.3 23.0 24.1 40.6 40.4 37.2 38.5 39.2 82.9 93.0 92.2 106.6 21.3 42.5 NA 12.8 47.2 NA 13.6 100

0.5 1.3 6.4 2.9 1.6 3.4 1.0 2.9 1.3 0.8 0.3

1.0

b/a ratio

1.0

12.0 2.6 1.6 1.4

1.0

a

Fold activation relative to maximum activation obtained with E2 (20 nM) for ERa and b. The compounds were tested in at least three separate experiments. b Binding affinities were determined by a competitive binding assay using [3H]-E2. Fold affinities relative to maximum activation obtained with E2 (1 nM) for ERa and b. The compounds were tested in at least three separate experiments. c NA means not active, which is for compounds producing transactivation activity or binding to ER lower lower than 10% at 20 mM. d The concentration of E2 for transactivation activity is 20 nM and that of E2 for the competitive binding affinity assay is 1 nM.

also demonstrated that, despite the high homology, ligands can be made to discriminate between the two ER subtypes. These findings suggest that further elaboration of the azaisoflavone scaffold as well as more sophisticate tuning with the appropriate substitution

will be the next strategy to explore those applications. We anticipate that these azaisoflavones might work as a useful pharmacological tool for development of therapeutic agents to treat ER mediated disease.

Fig. 4. A comparison of putative binding modes of azaisoflavone 3a with those of genistein in the active sites of hERa and hERb.

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Fig. 5. Putative binding modes of N-alkylated daidzein analogs 2bed when docked into the X-ray crystal structure of ERa and ERb.

5. Experimental 5.1. General procedures Most of the reagents and solvents were purchased from Aldrich chemicals and used without purification. Unless indicated, all anhydrous solvents were distilled under nitrogen condition. Acetonitrile, dichloroethane, pyridine and dimethylformamide were distilled from calcium hydride under nitrogen. Column chromatography was performed using silica gel 60 (230e400 mesh, Merck) with the indicated solvents. Thin-layer chromatography (TLC) was performed using Kieselgel 60 F254 plates (Merck). IR spectra were recorded on a JASCO FT/IR 430 spectrophotometer. NMR spectra were recorded on a Varian YH 400 spectrometer (1H 400 MHz and 13C 100 MHz). Chemical shifts are expressed in parts per million (ppm, d) relative to an internal standard, tetramethylsilane. 1H NMR data are reported in the order of chemical shift, multiplicity (s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet

and/or multiple resonances), number of protons and coupling constant in hertz (Hz). Mass spectra were recorded on a JEOL GCmate II spectrometer with glycerol as a matrix for the FAB-MS. 5.2. Synthesis of compounds 5.2.1. 3-(4-hydroxyphenyl)-1H-quinolin-4-one (1a) A solution of quinolone 8a (100 mg, 0.39 mmol), acetic acid and HBr (0.1 ml, 1.984 mmol) was stirred at 120  C for 3 days. The reaction mixture was cooled to rt to form precipitates. The resulted precipitates were filtered and washed with water and EtOAc thoroughly. The residue was purified by column chromatography (EtOAc/toluene/EtOH ¼ 1:1:1) to give quinolone 1a (79 mg, 84%): IR (neat, cm
1) 3414, 1614, 1577, 1373, 1262, 1181; 1H NMR (400 MHz, DMSO-d6) d 12.23 (1H, s), 8.20 (1H, dd, J ¼ 8.4, 0.8 Hz), 8.16 (1H, s), 7.59e7.68 (2H, m), 7.49e7.46 (2H, m), 7.36 (1H, dt, J ¼ 7.2, 1.6 Hz), 6.76 (2H, dt, J ¼ 8.8, 3.0 Hz); 13C NMR (100 MHz, DMSO-d6) d 175.0, 156.8, 139.8, 138.1, 132.1, 130.2, 127.2, 126.2, 126.0, 123.9, 120.6,

Fig. 6. Cytotoxic effects of genistein, daidzein, and azaisoflavone analogs on MCF-7 breast cancer cells. Each experiment was performed three times independently and results were expressed as means ± SD. One-way ANOVA with Dunnett's posttest was performed for each compound. Treatment means that are significantly different from control are indicated as *p < 0.05, **p < 0.01 and ***p < 0.001.

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118.9, 115.4; LRMS (FAB) m/z 238.1 (M þ Hþ); HRMS (FAB) calcd for C15H12N O2, 238.0868; found: 238.0865 (M þ H)þ.

LRMS (FAB) m/z 268.1 (M þ Hþ); HRMS (FAB) calcd for C16H14N O3, 268.0974; found: 268.0975 (M þ H)þ.

5.2.2. 1-Methyl-3-(4-hydroxyphenyl)-1H-quinolin-4-one (1b) This compound was prepared from 8b using the same procedure as described for the preparation of 1a: Yield 75%; IR (neat, cm
1) 3408, 1644, 1518, 1451, 1350, 1159; 1H NMR (400 MHz, DMSO-d6) d 10.39 (1H, s), 9.40 (1H, s), 8.10 (1H, s), 7.42 (2H, d, J ¼ 8.4 Hz), 6.75 (2H, d, J ¼ 8.4 Hz), 6.22 (1H, s), 6.09 (1H, s), 3.72 (3H, s); 13C NMR (100 MHz, DMSO-d6) d 179.0, 164.8, 163.2, 157.0, 144.2, 142.8, 130.3, 129.6, 125.7, 118.6, 115.5, 108.2, 98.4, 91.1, 41.4; LRMS (FAB) m/z 252.1 (M þ Hþ); HRMS (FAB) calcd for C16H14N O2, 252.1025; found: 252.1027 (M þ H)þ.

5.2.7. 7-hydroxy-3-(4-hydroxyphenyl)-1-ethyl-1H-quinolin-4-one (2c) This compound was prepared from 9c using the same procedure as described for the preparation of 1a: Yield 83%; IR (neat, cm
1) 3337, 2855, 1734, 1457, 1257, 1031; 1H NMR (400 MHz, CD3OD) d 8.26 (1H, d, J ¼ 8.8 Hz), 8.01 (1H, s), 7.44 (2H, d, J ¼ 8.8 Hz), 6.95 (1H, d, J ¼ 2.4 Hz), 6.93 (1H, dd, J ¼ 2.4,8.8 Hz), 6.82 (2H, d, J ¼ 8.8 Hz), 4.31 (2H, q, J ¼ 14.4 Hz), 1.48 (3H, t, J ¼ 7.2 Hz); 13C NMR (100 MHz, CD3OD) d 183.2, 171.4, 161.3, 156.1, 143.8, 135.1, 131.1, 119.4, 116.0, 107.5, 100.5, 97.3, 88.4, 71.5, 59.8, 30.7, 22.8; LRMS (FAB) m/z 282.1 (M þ Hþ); HRMS (FAB) calcd for C17H16N O3, 282.1130; found: 282.1129 (M þ H)þ.

5.2.3. 1-Ethyl-3-(4-hydroxyphenyl)-1H-quinolin-4-one (1c) This compound was prepared from 8c using the same procedure as described for the preparation of 1a: Yield 81%; IR (neat, cm
1) 3380, 1612, 1515, 1269, 838, 763; 1H NMR (400 MHz, DMSO-d6) d 8.27 (1H, d, J ¼ 8.0 Hz), 8.22 (1H, s), 7.75e7.69 (2H, m), 7.51 (2H, d, J ¼ 8.4 Hz), 7.36 (1H, t, J ¼ 7.2 Hz), 6.75 (2H, d, J ¼ 8.4 Hz), 4.35 (2H, q, J ¼ 6.8 Hz), 3.72 (1H, s), 1.34 (1H, t, J ¼ 6.8 Hz); 13C NMR (100 MHz, DMSO-d6) d 174.5, 156.9, 142.9, 139.1, 132.5, 130.3, 129.0, 127.0, 126.9, 123.9, 120.9, 117.0, 115.3, 47.9, 15.1; LRMS (FAB) m/z 266.1 (M þ Hþ); HRMS (FAB) calcd for C17H16N O2, 266.1181; found: 266.1180 (M þ H)þ. 5.2.4. 1-propyl-3-(4-hydroxyphenyl)-1H-quinolin-4-one (1d) This compound was prepared from 8d using the same procedure as described for the preparation of 1a: Yield 72%; IR (neat, cm
1) 3195, 1610, 1566, 1541, 1512, 1492, 1330, 1231, 840, 750; 1H NMR (400 MHz, CDCl3 þ CD3OD) d 8.52 (1H, d, J ¼ 8.4 Hz), 7.67e7.71 (1H, m), 7.51 (1H, d, J ¼ 8.4 Hz), 7.34e7.46 (2H, m), 7.45 (2H, d, J ¼ 8.8 Hz), 6.89 (2H, d, J ¼ 8.8 Hz), 4.19 (2H, dd, J ¼ 7.6, 7.2 Hz), 1.94 (2H, m), 1.03 (3H, dd, J ¼ 7.6, 7.2 Hz); 13C NMR (100 MHz, CDCl3 þ CD3OD) d 176.3, 156.2, 142.3, 138.9, 130.0, 127.3, 126.9, 126.3, 123.8, 122.0, 115.3, 115.2, 55.0, 22.2, 11.0; LRMS (FAB) m/z 280.1 (M þ Hþ); HRMS (FAB) calcd for C18H18N O2, 280.1338; found: 280.1336 (M þ H)þ. 5.2.5. 7-Hydroxy-3-(4-hydroxyphenyl)-1H-quinolin-4-one (2a) A solution of quinolone 9a (9.5 mg, 0.034 mmol), pyridine (0.5 mL) and HBr (1 mL) was stirred at 80  C overnight. The reaction mixture was cooled to rt, diluted and extracted with EtOAc. The organic layer was washed with water and brine, then dried over anhydrous MgSO4 and concentrated in vacuo. The residue was purified by column chromatography (CHCl3/EtOAc/MtOH ¼ 20:1:2) to give 2a (2.3 mg, 27%): IR (neat, cm
1) 3263, 2924, 1591, 1460, 1235, 840; 1H NMR (400 MHz, DMSO-d6) d 11.57 (1H, d, J ¼ 5.6 Hz), 10.20 (1H, br s), 9.29 (1H, s), 8.00 (1H, d, J ¼ 8.8 Hz), 7.87 (1H, d, J ¼ 5.6 Hz), 7.48 (2H, d, J ¼ 8.8 Hz), 6.82 (1H, d, J ¼ 2.4 Hz), 6.73e6.78 (3H, m); 13C NMR (100 MHz, DMSO-d6) d 175.0, 160.6, 156.3, 141.5, 137.0, 129.9, 128.0, 127.4, 119.8, 119.6, 115.0, 114.3, 101.2; LRMS (FAB) m/z 254.1 (M þ Hþ); HRMS (FAB) calcd for C15H12N O3, 254.0817; found: 254.0814 (M þ H)þ. 5.2.6. 7-hydroxy-3-(4-hydroxyphenyl)-1-methyl-1H-quinolin-4one (2b) This compound was prepared from 9b using the same procedure as described for the preparation of 1a: Yield 58%; IR (neat, cm
1) 3350, 2920, 1621, 1535, 1517, 1331, 1254, 1193; 1H NMR (400 MHz, CD3OD) d 8.27 (1H, d, J ¼ 8.8 Hz), 8.00 (1H, s), 7.45 (2H, d, J ¼ 8.8 Hz), 6.97 (1H, dd, J ¼ 2.4, 8.8 Hz), 6.94 (1H, d, J ¼ 2.4 Hz), 6.84 (1H, d, J ¼ 8.8 Hz), 3.89 (3H, s); 13C NMR (100 MHz, CD3OD) d 195.7, 180.0, 164.8, 151.7, 144.9, 131.2, 120.9, 116.0, 101.3, 100.7, 65.7, 54.0, 41.1;

5.2.8. 7-hydroxy-3-(4-hydroxyphenyl)-1-propyl-1H-quinolin-4one (2d) This compound was prepared from 9d sing the same procedure as described for the preparation of 1a: Yield 82%; IR (neat, cm
1) 3393, 2955, 2922, 2850, 1739, 1462, 1244, 1021; 1H NMR (400 MHz, CD3OD) d 8.27 (1H, d, J ¼ 8.8 Hz), 8.01 (1H, s), 7.44 (2H, d, J ¼ 8.8 Hz), 6.96e6.94 (2H, m), 6.84 (2H, d, J ¼ 8.8 Hz), 4.23 (2H, t, J ¼ 7.2 Hz), 1.92 (2H, q, J ¼ 7.2 Hz), 1.02 (3H, t, J ¼ 7.2 Hz); 13C NMR (100 MHz, CD3OD) d 177.2, 162.8, 157.7, 144.3, 142.5, 131.1, 129.8, 128.0, 122.5, 121.4, 116.0, 115.6, 100.7, 55.7, 23.1, 11.2; LRMS (FAB) m/z 296.1 (M þ Hþ); HRMS (FAB) calcd for C18H18N O3, 296.1287; found: 296.1280 (M þ H)þ. 5.2.9. 7-hydroxy-3-(4-hydroxyphenyl)-1-(3-methylbutyl)-1Hquinolin-4-one (2e) This compound was prepared from 9e using the same procedure as described for the preparation of 1a: Yield 52%; IR (neat, cm
1) 3120, 2956, 1617, 1515, 1443, 1267, 1025; 1H NMR (400 MHz, CD3OD) d 8.27 (1H, d, J ¼ 8.8 Hz), 8.06 (1H, s), 7.79 (1H, d, J ¼ 2.4 Hz), 7.43 (1H, dd, J ¼ 2.4,8.8 Hz), 7.00e6.93 (4H, m), 4.29 (2H, t, J ¼ 7.2 Hz), 7.00e6.93 (4H, m), 3.97 (3H, s), 1.78 (3H, m), 1.06 (3H, s), 1.04 (3H, s); 13C NMR (100 MHz, CD3OD) d 177.1, 163.7, 157.7, 144.0, 142.4, 131.2, 129.7, 128.0, 122.6, 121.1, 116.1, 116.0, 100.7, 52.8, 38.6, 27.2, 22.7; LRMS (FAB) m/z 324.2 (M þ Hþ); HRMS (FAB) calcd for C20H22N O3, 324.1600; found: 324.1602 (M þ H)þ. 5.2.10. 7-hydroxy-3-(4-hydroxyphenyl)-1-benzyl-1H-quinolin-4one (2f) This compound was prepared from 9f using the same procedure as described for the preparation of 1a: Yield 37%; IR (neat, cm
1) 3423, 3214, 1616, 1516, 1327, 1270, 1222, 837; 1H NMR (400 MHz, CD3OD) d 8.24 (1H, d, J ¼ 8.8 Hz), 8.15 (1H, s), 7.46 (2H, d, J ¼ 8.4 Hz), 7.32e7.35 (2H, m), 7.24e7.28 (1H, m), 7.19e7.21 (2H, m), 6.87 (1H, dd, J ¼ 8.8, 2.4 Hz), 6.80e6.83 (3H, m), 5.48 (2H, s)); 13C NMR (100 MHz, CDCl3 þ CD3OD) d 176.2, 161.0, 156.0, 142.4, 141.3, 134.9, 129.9, 128.9, 128.7, 127.9, 126.3, 125.9, 121.7, 114.9, 114.4, 100.1, 56.4; LRMS (FAB) m/z 344.1 (M þ Hþ); HRMS (FAB) calcd for C22H18N O3, 344.1287; found: 344.1285 (M þ H)þ. 5.2.11. 5,7-dihydroxy-3-(4-hydroxyphenyl)-1H-quinolin-4-one (3a) This compound was prepared from 10a using the same procedure as described for the preparation of 1a: Yield 87%; IR (neat, cm
1) 3294, 1654, 616, 1566, 1514, 1440,1382, 1275, 1199, 884, 829, 695, 655; 1H NMR (400 MHz, DMSO-d6) d 12.02 (1H, d, J ¼ 6 Hz), 10.11 (1H, s), 7.43-7.41 (1H, m), 7.42 (2H, dd, J ¼ 6.8,2.0 Hz), 6.74 (2H, dd, J ¼ 6.8, 2.0 Hz), 6.26 (1H, d, J ¼ 2.0 Hz), 5.97 (1H, d, J ¼ 2.0 Hz); 13C NMR (100 MHz, DMSO-d6) d 179.7, 163.7, 156.9, 142.2, 138.5, 130.3, 126.1, 118.6, 115.4, 108.1, 97.9, 91.9; LRMS (FAB)

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m/z 270.1 (M þ Hþ); HRMS (FAB) calcd for C15H12N O4, 270.0766; found: 270.0762 (M þ H)þ. 5.2.12. 5,7-dihydroxy-3-(4-hydroxyphenyl)-1-methyl-1H-quinolin4-one (3b) This compound was prepared from 10b using the same procedure as described for the preparation of 1a: Yield 88%; IR (neat, cm
1) 3407, 1644, 1561, 1517, 1451, 1349, 1159; 1H NMR (400 MHz, DMSO-d6) d 10.39 (1H, s), 9.40 (1H, s), 8.10 (1H, s), 7.43 (2H, d, J ¼ 8.4 Hz), 6.75 (2H, d, J ¼ 8.4 Hz), 6.22 (1H, s), 6.09 (1H, s), 3.72 (3H, s); 13C NMR (100 MHz, DMSO-d6) d 179.0, 164.8, 163.2, 157.0, 144.2, 142.8, 130.3, 129.6, 125.7, 118.6, 115.5, 108.2, 98.4, 91.1; LRMS (FAB) m/z 284.1 (M þ Hþ); HRMS (FAB) calcd for C16H14N O4, 284.0923; found: 284.0918 (M þ H)þ. 5.2.13. 5,7-dihydroxy-3-(4-hydroxyphenyl)-1-ethyl-1H-quinolin-4one (3c) This compound was prepared from 10c using the same procedure as described for the preparation of 1a: Yield 85%; IR (neat, cm
1) 2971, 1612, 1509, 1459, 1354, 1288, 1245, 1161, 1121, 1073, 1031, 951; 1H NMR (400 MHz, DMSO-d6) d 9.42 (1H, s), 8.11 (1H, s), 7.44 (2H, d, J ¼ 8.8 Hz), 6.74 (2H, d, J ¼ 8.8 Hz), 6.29 (1H, d, J ¼ 2.0 Hz), 6.07 (1H, d, J ¼ 2.0 Hz), 4.19-4.17 (2H, m),1.31 (3H, t, J ¼ 7.2 Hz); 13C NMR (100 MHz, DMSO-d6) d 179.0, 165.0, 163.2, 157.0, 143.2, 141.6, 130.4, 129.6, 128.9, 125.7, 119.0, 115.4, 108.5, 98.2, 90.8, 48.5, 14.5; LRMS (FAB) m/z 298.1 (M þ Hþ); HRMS (FAB) calcd for C17H16N O4, 298.1079; found: 298.1074 (M þ H)þ. 5.2.14. 5,7-dihydroxy-3-(4-hydroxyphenyl)-1-propyl-1H-quinolin4-one (3d) This compound was prepared from 10d using the same procedure as described for the preparation of 1a: Yield 32%; IR (neat, cm
1) 3258, 1642, 1560, 1515, 1446, 1362, 1157, 836; 1H NMR (400 MHz, CD3OD) d 7.84 (1H, s), 7.36 (2H, d, J ¼ 8.4 Hz), 6.79 (2H, d, J ¼ 8.4 Hz), 6.27 (1H, s), 6.14 (1H, s), 4.06 (2H, t, J ¼ 7.2 Hz), 1.83 (2H, m), 0.96 (3H, t, J ¼ 7.2 Hz); 13C NMR (100 MHz, CD3OD) d 178.9, 164.0, 162.9, 156.5, 142.9, 141.6, 129.8, 125.5, 119.7, 114.7, 108.3, 97.7, 90.2, 54.8, 21.3, 9.7; LRMS (FAB) m/z 312.1 (M þ Hþ); HRMS (FAB) calcd for C18H18N O4, 312.1236; found: 312.1243 (M þ H)þ. 5.2.15. 1-(2-aminophenyl)ethanone (4a) To a solution of boron trichloride (2.77 g, 23.63 mmol) in dichloromethane was added a solution of aniline (2.00 g, 21.48 mmol) in 1,2-dichloroethane (15 mL) at 0  C. To the mixture was added aluminum chloride (3.15 g, 23.63 mmol) and acetonitrile (0.88 g, 21.48 mmol) and the mixture was refluxed at 80  C for 20 h. After the reaction was completed, the reaction mixture was cooled to 0  C, then 2 N HCl was added. The mixture was stirred at 80  C for 30 min. The reaction mixture was extracted with dichloromethane. The organic layer was washed with 1 N NaOH and brine, dried over anhydrous MgSO4, and concentrated in vacuo to give amino phenylketone 4a (2.67 g, 92%) as a yellow solid: IR (neat); 3460, 3341, 1644, 1615, 1242, 1162; 1H NMR (400 MHz, CDCl3) d 7.71 (1H, dd, J ¼ 8.4, 1.6 Hz), 7.26 (1H, ddd, J ¼ 8.4, 1.6 Hz), 6.65 (2H, m), 6.27 (2H, br s), 2.58 (3H, s); 13C NMR (100 MHz, CDCl3) d 200.8, 150.2, 134.4, 132.0, 118.2, 117.2, 115.7, 27.9. 5.2.16. 1-(2-amino-4-methoxyphenyl)ethanone (4b) This compound was prepared from m-anisidine using the same procedure as described for the preparation of 4a: Yield 56%; IR (neat, cm
1) 3450, 3332, 1619, 1223; 1H NMR (400 MHz, CDCl3) d 7.63 (1H, d,, J ¼ 8.8 Hz), 6.41 (2H, brs), 6.23 (1H, dd, J ¼ 8.8, 2.4 Hz), 6.06 (1H, d, J ¼ 2.4 Hz), 3.79 (3H, s), 2.51 (3H, s); 13C NMR (100 MHz, CDCl3) d 198.8, 164.2, 152.7, 134.0, 112.7, 104.3, 99.0, 55.0, 27.5.

5.2.17. 1-(2-amino-4,6-dimethoxyphenyl)ethanone (4c) This compound was prepared from 3,5-dimethoxyaniline using the same procedure as described for the preparation of 4a: Yield 81%; IR (neat, cm
1) 3435, 3282, 2973, 1615, 1578, 1456, 1426, 1363, 1322, 1247, 1208,1168, 1139, 953, 813; 1H NMR (400 MHz, CDCl3) d 6.34 (2H, s), 5.73 (1H, d, J ¼ 2.4 Hz), 5.68 (1H, d, J ¼ 2.4 Hz), 3.79 (3H, s), 3.75 (3H, s), 2.51 (3H, s); 13C NMR (100 MHz, CDCl3) d 200.4, 164.2, 163.7, 153.8, 105.9, 92.2, 88.5, 55.5, 55.4, 34.1. 5.2.18. 1-(2-aminophenyl)-3-(4-methoxyphenyl)propenone (5a) A mixture of aminophenyl ketone 4a (2.50 g, 18.51 mmol), panisaldehyde (2.52 g, 18.51 mmol), a small amount of sodium hydroxide (1-2 pallets), and ethanol (3 mL) was stirred at rt for 10 h. After the reaction was completed, the solvent was removed in vacuo. The residue was diluted and extracted with EtOAc. The organic layer was washed with water and brine, then dried over anhydrous MgSO4 and concentrated in vacuo to give 2'-aminochalcone 5a (4.27 g, 91%) as a yellow solid : IR (neat, cm
1) 3463, 2925, 1568, 1259, 1028, 800, 748, 657; 1H NMR (400 MHz, CDCl3) d 7.79 (1H, d, J ¼ 8.4 Hz), 7.65 (1H, d, J ¼ 15.6 Hz), 7.52 (2H, d, J ¼ 7.6 Hz), 7.43 (1H, d, J ¼ 15.6 Hz), 7.20 (1H, m), 6.86 (2H, d, J ¼ 8.8 Hz), 6.63 (2H, d, J ¼ 8.0 Hz), 6.23 (2H, s), 3.79 (3H, s); 13C NMR (100 MHz, CDCl3) d 192.0, 151.1, 143.0, 134.3, 131.1, 130.2, 128.2, 120.9, 117.5, 116.0, 114.6, 55.6, 29.9. 5.2.19. 1-(2-amino-4-methoxyphenyl)-3-(4-methoxyphenyl) propenone (5b) This compound was prepared from 4b using the same procedure as described for the preparation of 5a: Yield 81%; IR (neat, cm
1) 3406, 3290, 2964, 2836, 1635, 1568, 1509, 1421, 1380, 1348, 1288, 1250, 1211, 1176, 1144, 990, 957; 1H NMR (400 MHz, CDCl3) d 7.81 (1H, d, J ¼ 8.8 Hz), 7.69 (1H, d, J ¼ 15.2 Hz), 7.57 (2H, d, J ¼ 8.8 Hz), 7.47 (2H, d, J ¼ 15.2 Hz), 6.92 (2H, d, J ¼ 8.8 Hz), 6.56 (2H,brs), 6.27 (1H, dd, J ¼ 8.8, 2.4 Hz), 6.11 (1H, d, J ¼ 3.0 Hz), 3.84 (3H, s), 3.81 (3H, s); 13C NMR (100 MHz, CDCl3) d 181.9, 169.9, 164.8, 161.9, 144.5, 144.4, 132.6, 130.5, 127.8, 120.4, 116.5, 114.7, 109.7, 104.5, 55.8, 55.6, 31.1, 25.9. 5.2.20. 1-(2-amino-4,6-dimethoxyphenyl)-3-(4-methoxyphenyl) propenone (5c) This compound was prepared from 4c using the same procedure as described for the preparation of 5a: Yield 56%; IR (neat, cm
1) 3432, 3333, 2938, 2360, 1571, 1509, 1457, 1419, 1339, 1282, 1245, 1211, 1163, 1026, 970; 1H NMR (400 MHz, CDCl3) d 7.56 (1H, d, J ¼ 15.6 Hz), 7.50 (2H, d, J ¼ 8.8 Hz), 7.36 (1H, d, J ¼ 15.6 Hz), 6.87 (2H, d, J ¼ 8.8 Hz), 5.99 (2H, s), 5.80 (1H, d, J ¼ 2.4 Hz), 5.75 (1H, d, J ¼ 2.4 Hz), 3.82 (3H, s), 3.81 (3H, s), 3.77 (3H, s); 13C NMR (100 MHz, CDCl3) d 191.6, 164.1, 162.8, 161.0, 153.1, 139.5, 129.9, 128.9, 127.6, 114.4, 107.2, 92.5, 89.0. 5.2.21. N-[2-[3-(4-methoxyphenyl)-1-oxo-2-propenyl]phenyl] acetamide (6a) To a solution of 2'-aminochalcone 5a (4.20 g, 16.58 mmol) in pyridine (40 mL) was added acetic anhydride (40 mL). The mixture was stirred at rt for 3 h. After the reaction was completed, the reaction mixture was extracted with EtOAc. The organic layer was washed with water and brine, dried over anhydrous MgSO4, and concentrated in vacuo to give a yellow solid. The residue was recrystallized with EtOAc and n-hexane to give 2'-acetamidochalcone 6a (3.27 g, 76%) as a pale yellow solid: IR (neat, cm
1) 3158, 1687, 1641, 1576, 1510, 1455, 1308, 1255, 1204, 1012, 838, 812; 1H NMR (400 MHz, CDCl3) d 11.53 (1H, s), 8.66 (1H, d, J ¼ 8.0 Hz), 7.93 (1H, dd, J ¼ 8.0, 1.4 Hz), 7.75 (1H, d, J ¼ 15.6 Hz), 7.59 (2H, d, J ¼ 3.2 Hz), 7.52 (1H, dt, J ¼ 7.8, 1.6 Hz), 7.41 (1H, d, J ¼ 15.6 Hz), 7.13 (1H, dt, J ¼ 8.2, 1.0 Hz), 6.92 (2H, dd, J ¼ 8.8, 4.8 Hz),

H.J. Gim et al. / European Journal of Medicinal Chemistry 85 (2014) 107e118

3.84 (3H, s), 2.22 (3H, s); 13C NMR (100 MHz, CDCl3) d 193.6, 169.6, 162.2, 145.8, 141.1, 134.6, 130.7, 130.6, 127.5, 123.9, 122.6, 121.4, 120.6, 114.7, 55.7, 25.7. 5.2.22. N-{5-methoxy-2-[3-(4-methoxyphenyl)acryloyl]phenyl} acetamide (6b) This compound was prepared from 5b using the same procedure as described for the preparation of 6a: Yield 61%; IR (neat, cm
1) 1700, 1605, 1512, 1452, 1419, 1291, 1235, 1202, 1176, 1158, 1235, 1202, 978, 835; 1H NMR (400 MHz, CDCl3) d 12.20 (1H, br s), 8.35 (1H, d, J ¼ 2.4 Hz), 7.82 (1H, d, J ¼ 8.8 Hz), 7.64 (1H, d, J ¼ 15.2 Hz), 7.48 (2H, d, J ¼ 8.8 Hz), 7.34 (1H, d, J ¼ 15.2 Hz), 6.83 (2H, d, J ¼ 8.8 Hz), 6.54 (1H, dd, J ¼ 8.8, 2.4 Hz), 3.79 (3H, s), 3.75 (3H, s), 2.17 (3H, s); 13C NMR (100 MHz, CDCl3) d 191.8, 169.9, 164.7, 161.9, 144.5, 144.4, 132.6, 130.5, 127.8, 120.4, 116.5, 114.7, 109.7, 104.5, 55.8, 55.6, 25.9. 5.2.23. N-{3,5-dimethoxy-2-[3-(4-methoxyphenyl)acryloyl]phenyl} acetamide (6c) This compound was prepared from 5c using the same procedure as described for the preparation of 6a: Yield 89%; IR (neat, cm
1) 2941, 1699, 1605, 1578, 1513, 1471, 1365, 1336, 1294, 1262, 1234, 1203, 1176, 1158, 1108, 1031, 975; 1H NMR (400 MHz, CDCl3) d 10.99 (1H, s), 7.88 (1H, d, J ¼ 2.4 Hz), 7.62 (1H, d, J ¼ 15.6 Hz), 7.49e7.52 (2H, m), 7.22e7.27 (1H, m), 6.87e6.91 (2H, m), 6.22 (1H, d, J ¼ 2.0 Hz), 3.86 (3H, s), 3.85 (3H, s), 3.82 (3H, s), 2.17 (3H, s); 13C NMR (100 MHz, CDCl3) d 200.1, 170.3, 164.5, 161.8, 142.3, 141.8, 131.1, 128.2, 126.0, 114.6, 110.2, 97.8, 94.1, 58.1, 57.6, 57.0, 24.1, 38.9. 5.2.24. N-[2-[3,3-dimethoxy-2-(4-methoxyphenyl)-1-oxopropyl] phenyl]acetamide (7a) A solution of thallium(III) nitrate trihydrate (3.31 g, 7.45 mmol) in trimethyl orthoformate (7 mL) was added to a solution of 2'acetamidochalcone 6a (2.00 g, 6.77 mmol) in trimethyl orthoformate (15 mL) over a period of 15 min and the mixture was stirred at rt for 4 h. After the reaction was completed, thallium(I) was removed through the filtration. The filtrate was neutralized by addition of 5% aqueous solution of NaOH and extracted with dichloromethane. The combined extracts were washed with water and brine, dried over anhydrous MgSO4, and concentrated in vacuo to give acetal 7a (2.37 g, 98%) as a brown semisolid: IR (neat, cm
1) 3445, 1515, 1382, 1243; 1H NMR (400 MHz, CDCl3) d 11.53 (1H, s), 8.66 (1H, dd, J ¼ 8.8, 0.8 Hz), 7.94 (1H, dd, J ¼ 8.4, 1.6 Hz), 7.46 (1H, dt, J ¼ 7.6, 1.6 Hz), 7.28 (2H, dd, J ¼ 6.4, 2.0 Hz), 7.03 (1H, dd, J ¼ 7.8, 1.4 Hz), 6.83 (2H, dd, J ¼ 6.4, 2.0 Hz), 5.02 (1H, d, J ¼ 8.4 Hz), 4.85 (1H, d, J ¼ 8.4 Hz), 4.09 (1H, q, J ¼ 7.2 Hz), 3.74 (3H, s), 3.39 (3H, s), 3.18 (3H, s), 2.21 (3H, s); 13C NMR (100 MHz, CDCl3) d 135.2, 131.2, 130.0, 122.6, 121.0, 114.6, 106.7, 56.8, 55.8, 55.4, 54.7, 25.8. 5.2.25. N-{2-[3,3-dimethoxy-2-(4-methoxyphenyl)propionyl]-5methoxyphenyl}acetamide (7b) This compound was prepared from 6b using the same procedure as described for the preparation of 7a: Yield 32%; IR (neat, cm
1) 2935, 1612, 1512, 1457, 1245, 1110, 818; 1H NMR (400 MHz, CDCl3) d 12.07 (1H, br s), 8.38 (1H, d, J ¼ 2.4 Hz), 7.92 (1H, d, J ¼ 8.8 Hz), 7.31 (2H, d, J ¼ 8.8 Hz), 6.83 (2H, d, J ¼ 8.8 Hz), 6.55 (1H, dd, J ¼ 8.8, 2.4 Hz), 5.05 (1H, d, J ¼ 8.8 Hz), 4.81 (1H, d, J ¼ 8.8 Hz), 3.81 (3H, s), 3.74 (3H, s), 3.41 (3H, s), 3.20 (3H, s), 2.24 (3H, s); 13C NMR (100 MHz, CDCl3) d 170.0, 165.0, 159.2, 144.8, 133.4, 129.9, 127.5, 114.8, 114.5, 109.8, 106.7, 104.3, 56.3, 55.8, 55.7, 55.4, 54.8, 51.5, 26.0. 5.2.26. N-{2-[3,3-dimethoxy-2-(4-methoxyphenyl)propionyl]-3,5dimethoxyphenyl}acetamide (7c) This compound was prepared from 6c using the same procedure as described for the preparation of 7a: Yield 98%; IR (neat,

115

cm
1) 3395, 1700, 1654, 1614, 1578, 1511, 1451, 1430, 1335,1294, 1242, 1161, 1109, 1069, 807; 1H NMR (400 MHz, CDCl3) d 10.64 (1H, s), 7.81 (1H, s), 7.31 (2H, d, J ¼ 8.8 Hz), 6.83 (2H, d, J ¼ 8.8 Hz), 6.11 (1H, d, J ¼ 2.4 Hz), 4.93 (1H, d, J ¼ 8.8 Hz), 4.81 (1H, d, J ¼ 8.4 Hz), 3.80 (3H, s), 3.75 (3H, s), 3.75 (3H, s), 3.13 (3H, s), 2.16 (3H, s); 13C NMR (100 MHz, CDCl3) d 203.6, 169.4, 164.3, 161.1, 158.9, 141.9, 130.2, 128.0, 113.9, 107.8, 97.5, 94.5, 60.5, 55.8, 55.6, 55.4, 55.1, 54.5, 25.7. 5.2.27. 3-(4-methoxyphenyl)-4(1H)-quinolinone (8a) To a solution of acetal 7a (2.37 g, 6.63 mmol) in ethanol was added 5% HCl and the mixture was stirred at rt for 10 min, then warmed to 50  C and stirred for 2 h. The reaction mixture was cooled to rt to form light brown precipitates. The precipitates were filtered and recrystallized with ethanol to give quinolone 8a (1.52 g, 91%): IR (neat, cm
1) 3062, 2360, 1562, 1515, 1340, 1296, 1244, 1022, 819, 754, 615; 1H NMR (400 MHz, DMSO-d6) d 8.16 (1H, dd, J ¼ 8.0, 1.2 Hz), 8.06 (1H, d, J ¼ 4.0 Hz), 7.62 (3H, m), 7.53 (1H, dd, J ¼ 7.6, 0.6 Hz), 7.29 (1H, dt, J ¼ 7.4, 1.2 Hz), 6.91 (2H, td, J ¼ 8.0, 3.4 Hz), 3.74 (3H, s); 13C NMR (100 MHz, DMSO-d6) d 175.4, 158.6, 139.9, 138.1, 132.1, 120.1, 129.1, 126.2, 123.8, 120.2, 118.8, 118.7, 113.9, 55.7; LRMS (FAB) m/z 252.1 (M þ Hþ); HRMS (FAB) calcd for C16H14N O2, 252.1025; found: 252.1017 (M þ H)þ. 5.2.28. 3-(4-methoxyphenyl)-1-methyl-1H-quinolin-4-one (8b) To a solution of quinolone 8a (100 mg, 0.321 mmol) and NaH (60% dispersion in mineral oil, 19.3 mg, 0.482 mmol) in DMF (1.5 mL) was added iodoethane (91.2 mg, 0.642 mmol). The mixture was stirred at rt for 3 h. The reaction was quenched with water and extracted with EtOAc. The organic layer was washed with water, dried over MgSO4, and concentrated in vacuo. The residue was purified by column chromatography (CHCl3/EtOAc/ MeOH ¼ 2:1:0.2) to give 8b (102.4 mg, 98%): IR (neat, cm
1) 3512, 2925, 1613, 1574, 1510, 1460, 1242, 1177, 1070, 1028; 1H NMR (400 MHz, DMSO-d6) d 7.89 (1H, s), 7.49 (2H, d, J ¼ 8.8 Hz), 6.87 (2H, d, J ¼ 8.8 Hz), 6.45 (1H, s), 6.39 (1H, s), 3.87 (3H, s), 3.75 (3H, s), 3.72 (6H, s); 13C NMR (100 MHz, DMSO-d6) d 174.6, 162.7, 162.6, 158.5, 144.6, 141.7, 130.3, 129.1, 121.9, 113.7, 112.4, 95.1, 91.2, 56.4, 56.2, 55.7, 41.5; LRMS (FAB) m/z 266.1 (M þ Hþ); HRMS (FAB) calcd for C17H16N O2, 266.1181; found: 266.1173 (M þ H)þ. 5.2.29. 3-(4-methoxyphenyl)-1-ethyl-1H-quinolin-4-one (8c) This compound was prepared from 8a using the same procedure as described for the preparation of 8b: Yield 81%: IR (neat, cm
1) 2990, 2833, 1571, 1512, 1329, 1241, 1176, 1031, 835, 758; 1H NMR (400 MHz, DMSO-d6) d 8.27 (1H, d, J ¼ 8 Hz), 8.23 (1H, s), 7.49e7.65 (4H, m), 7.36 (1H, t, J ¼ 7.4 Hz), 6.93 (2H, d, J ¼ 7.2 Hz), 4.35 (2H, q, J ¼ 6.8 Hz), 3.75 (3H, s), 1.35 (3H, t, J ¼ 6.8 Hz); 13C NMR (100 MHz, DMSO-d6) d 174.9, 158.7, 142.9, 139.2, 132.8, 130.2, 128.8, 127.5, 127.2, 123.8, 120.4, 117.0, 113.9, 55.9, 47.8, 15.1; LRMS (FAB) m/z 280.1 (M þ Hþ); HRMS (FAB) calcd for C18H18N O2, 280.1338; found: 280.1347 (M þ H)þ. 5.2.30. 3-(4-methoxyphenyl)-1-propyl-1H-quinolin-4-one (8d) This compound was prepared from 8a using the same procedure as described for the preparation of 8b: Yield 98%: IR (neat, cm
1) 2963, 2933, 1623, 1583, 1512, 1490, 1246, 1178, 1035, 835, 760; 1H NMR (400 MHz, CDCl3) d 8.49 (1H, d, J ¼ 8.0 Hz), 7.60 (1H, d, J ¼ 2.0 Hz), 7.54 (2H, d, J ¼ 8.8 Hz), 7.51e7.56 (1H, m), 7.25e7.33 (2H, m), 6.85 (2H, d, J ¼ 8.8 Hz), 3.99 (2H, t, J ¼ 6.8 Hz), 3.73 (3H, s), 1.79 (2H, m), 0.90 (3H, t, J ¼ 7.6 Hz),; 13C NMR (100 MHz, CDCl) d 175.7, 158.6, 141.7, 138.9, 131.7, 129.7, 128.0, 127.5, 127.3, 123.3, 121.1, 115.2, 113.6, 55.2, 54.7, 22.2, 11.1; LRMS (FAB) m/z 294.1 (M þ Hþ); HRMS (FAB) calcd for C19H20N O2, 294.1494; found: 294.1495 (M þ H)þ.

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5.2.31. 7-methoxy-3-(4-methoxyphenyl)-2,3-dihydro-1H-quinolin4-one (9a) This compound was prepared using from 7b the same procedure as described for the preparation of 8a: Yield 30%; IR (neat) 2965, 1632, 1560, 1515, 1350, 1289, 1250, 1180, 1029 cm-1; IR (neat, cm
1) 3398, 3073, 2967, 1634, 1517, 1252, 1181, 1030, 829; 1H NMR (400 MHz, DMSO-d6) d 11.78 (1H, d, J ¼ 3.6 Hz), 8.05 (1H, d, J ¼ 9.2 Hz), 7.99 (1H, t, J ¼ 2.4 Hz), 7.60 (2H, d, J ¼ 8.4 Hz), 6.91 (4H, d, J ¼ 4.8 Hz), 3.83 (3H, s), 3.74 (3H, s); 13C NMR (100 MHz, DMSOd6) d 174.9, 162.3, 158.6, 141.6, 141.5, 137.8, 137.6, 130.1, 129.1, 128.1, 120.7, 120.0, 114.1, 113.9, 99.5, 55.1, 55.7; LRMS (FAB) m/z 282.1 (M þ Hþ); HRMS (FAB) calcd for C17H16N O3, 282.1130; found: 282.1134 (M þ H)þ. 5.2.32. 7-methoxy-3-(4-methoxyphenyl)-1-methyl-1H-quinolin-4one (9b) This compound was prepared from 9a using the same procedure as described for the preparation of 8b: Yield 95%: IR (neat, cm
1) 3584, 2924, 1618, 1575, 1509, 1482, 1331, 1252, 1213, 1178, 1123, 1065, 1033, 831; 1H NMR (400 MHz, CDCl3) d 8.48 (1H, d, J ¼ 8.8 Hz), 7.59 (3H, d, J ¼ 8.8 Hz), 7.00 (1H, dd, J ¼ 2.4,8.8 Hz), 6.94 (2H, d, J ¼ 8.8 Hz), 6.71 (1H, d, J ¼ 2.4 Hz), 3.94 (3H, s), 3.83 (3H, s), 3.78 (3H, s); 13C NMR (100 MHz, CDCl3) d 175.3, 162.4, 162.3, 158.4, 141.7, 129.5, 129.0, 127.8, 121.1, 113.4, 112.2, 97.4, 55.4, 55.1, 40.5; LRMS (FAB) m/z 296.1 (M þ Hþ); HRMS (FAB) calcd for C18H18N O3, 296.1287; found: 296.1284 (M þ H)þ. 5.2.33. 7-methoxy-3-(4-methoxy-phenyl)- 1-ethyl-1H-quinolin-4one (9c) This compound was prepared from 9a using the same procedure as described for the preparation of 8b: Yield 85% 1;H NMR (400 MHz, CDCl3) d 8.49 (1H, d, J ¼ 9.2 Hz), 7.62 (1H, s), 7.60 (2H, d, J ¼ 8.8 Hz), 6.98 (1H, dd, J ¼ 2.4,8.8 Hz), 6.94 (2H, d, J ¼ 8.8 Hz), 6.76 (1H, d, J ¼ 2.4 Hz), 4.15 (2H, q, J ¼ 14.4 Hz), 3.93 (3H, s), 3.83 (3H, s), 1.50 (3H, t, J ¼ 7.2 Hz); 13C NMR (100 MHz, CDCl3) d 175.3, 162.4, 162.3, 158.5, 140.5, 140.3, 129.7, 129.6, 127.9, 121.7, 121.6, 113.6, 111.8, 104.9, 97.7, 55.5, 55.2, 47.9, 14.2; LRMS (FAB) m/z 310.1 (M þ Hþ); HRMS (FAB) calcd for C19H20N O3, 310.1443; found: 310.1445 (M þ H)þ. 5.2.34. 7-methoxy-3-(4-methoxyphenyl)-1-propyl-1H-quinolin-4one (9d) This compound was prepared from 9a using the same procedure as described for the preparation of 8b: Yield 67% 1;H NMR (400 MHz, CD3OD) d 8.32 (1H, d, J ¼ 8.8 Hz), 8.02 (1H, s), 7.53 (2H, d, J ¼ 8.8 Hz), 7.05 (1H, dd, J ¼ 2.4,8.8 Hz), 6.99 (1H, d, J ¼ 2.4 Hz), 6.94 (2H, d, J ¼ 8.8 Hz), 4.26 (2H, t, J ¼ 7.2 Hz), 3.94 (3H, s), 3.80 (3H, s), 1.90 (2H, q, J ¼ 14.4 Hz), 1.48 (3H, t, J ¼ 7.2 Hz); 13C NMR (100 MHz, CD3OD) d 175.3, 162.3, 158.5, 141.3, 140.5, 129.6, 129.5, 127.9, 121.6, 121.0, 113.5, 111.6, 98.0, 55.4, 55.2, 54.7, 21.9, 11.1; LRMS (FAB) m/z 324.2 (M þ Hþ); HRMS (FAB) calcd for C20H22N O3, 324.1600; found: 324.1600 (M þ H)þ. 5.2.35. 7-methoxy-3-(4-methoxyphenyl)-1-(3-methylbutyl)-1Hquinolin-4-one (9e) To a solution of quinolone 9a (50 mg, 0.17 mmol) and NaH 60% dispersion in mineral oil (12 mg, 0.53 mmol) in DMF (1 mL) was added dimethylallyl bromide (41 mL, 0.35 mmol). The mixture was stirred at rt for 2 h. The reaction was quenched with water and extracted with EtOAc. The organic layer was washed with water, dried over MgSO4, and concentrated in vacuo. The residue was purified by column chromatography (n-hexane/EtOAc ¼ 5:2) to give N-isoprenylated compound (53 mg, 85%): IR (neat, cm
1) 3584, 1617, 1576, 1510, 1472, 1258, 1177, 1034, 831; 1H NMR (400 MHz, CDCl3) d 8.33 (1H, d, J ¼ 8.8 Hz), 8.13 (1H, s), 7.47 (2H, d, J ¼ 8.8 Hz),

7.18 (1H, dd, J ¼ 2.4,8.8 Hz), 7.08 (1H, d, J ¼ 2.4 Hz), 6.76 (2H, d, J ¼ 8.8 Hz), 5.39, (1H, t, J ¼ 7.2 Hz), 5.14 (2H, d, J ¼ 6.4 Hz), 4.03 (3H, s), 3.64 (3H, s), 1.95 (3H, s), 1.83 (3H, s). And then to a solution of Nisoprenylated compound (30 mg, 0.08 mmol) in ethanol was added Pd(OH)2 (24 mg, 80 wt%) and ammoniumformate (64.2 mg, 0.80 mmol) in H2O (0.5 mL) and stirred at rt for 18 h. The mixture was filtered through Celite pad and washed with ethanol. The liquor was concentrated in vacuo and purified by column chromatography (n-hexane/EtOAc ¼ 3:2) to give 9e (28 mg, 92%): 1H NMR (400 MHz, CDCl3) d 8.34 (1H, d, J ¼ 8.8 Hz), 8.13 (1H, s), 7.47 (2H, d, J ¼ 8.8 Hz), 7.18 (1H, dd, J ¼ 2.4,8.8 Hz), 7.08 (1H, d, J ¼ 2.4 Hz), 6.76 (2H, d, J ¼ 8.8 Hz), 4.35 (2H, t, J ¼ 7.2 Hz), 4.03 (3H, s), 3.64 (3H, s), 1.80e1.76 (3H, m), 1.95 (3H, s), 1.83 (3H, s); LRMS (FAB) m/z 352.2 (M þ Hþ); HRMS (FAB) calcd for C22H26NO3, 352.1913; found: 352.1913 (M þ H)þ. 5.2.36. 1-methoxy-7-benzyloxy-3-(4-benzyloxyphenyl)-1Hquinolin-4-one (9f) To a solution of quinolone 9a (65.0 mg, 0.231 mmol) and NaH 60% dispersion in mineral oil (18.5 mg, 0.462 mmol) in DMF (2 mL) was added benzyl bromide (33.6 mL, 0.277 mmol). The mixture was stirred at rt for 5 h. The reaction was quenched with water and extracted with EtOAc. The organic layer was washed with water, dried over MgSO4, and concentrated in vacuo. The residue was purified by column chromatography (n-hexane/EtOAc ¼ 2:3) to give 9f (53.5 mg, 62%): 1H NMR (400 MHz, CDCl3) d 8.45 (1H, d, J ¼ 9.2 Hz), 7.71 (1H, s), 7.61 (2H, d, J ¼ 8.8 Hz), 7.29e7.35 (3H, m), 7.17 (2H, d, J ¼ 6.8 Hz), 6.92 (2H, d, J ¼ 8.8 Hz), 6.90e6.93 (1H, m), 6.61 (1H, d, J ¼ 2.0 Hz), 5.26 (2H, s), 3.80 (3H, s), 3.72 (2H, s); 13C NMR (100 MHz, CDCl3) d 175.6, 162.4, 158.7, 141.7, 141.0, 135.3, 129.8, 129.4, 129.2, 128.2, 127.8, 126.1, 121.7, 121.6, 113.7, 112.4, 98.6, 56.7, 55.4, 55.3; LRMS (FAB) m/z 372.2 (M þ Hþ); HRMS (FAB) calcd for C24H22N O3, 372.1600; found: 372.1600 (M þ H)þ. 5.2.37. 5,7-dimethoxy-3-(4-methoxyphenyl)-1H-quinolin-4-one (10a) This compound was prepared from 7c using the same procedure as described for the preparation of 8a: Yield 93%; IR (neat, cm
1) 3368, 3232, 2592, 1644, 1601, 1514, 1472, 1411, 1310, 1243, 1203, 1183, 1164, 1108, 1073, 1037, 977, 945, 867, 832; 1H NMR (400 MHz, DMSO-d6) d 11.89 (1H, s), 7.89 (1H, s), 7.49 (2H, d, J ¼ 7.2 Hz), 6.89 (2H, d, J ¼ 7.2 Hz), 6.52 (1H, s), 6.35 (1H, s), 3.80 (3H, s), 3.78 (3H, s), 3.73 (3H, s); 13C NMR (100 MHz, DMSO-d6) d 173.7, 162.8, 161.5, 158.7, 143.9, 137.0, 130.5, 128.7, 121.6, 113.9, 111.2, 95.8, 91.9, 56.6, 56.1, 55.7, 31.4; LRMS (FAB) m/z 312.1 (M þ Hþ); HRMS (FAB) calcd for C18H18N O4, 312.1236; found: 312.1241 (M þ H)þ. 5.2.38. 5,7-dimethoxy-3-(4-methoxyphenyl)-1-methyl-1Hquinolin-4-one (10b) This compound was prepared from 10a using the same procedure as described for the preparation of 8b: Yield 83%; IR (neat, cm
1) 3512, 2925, 1613, 1574, 1510, 1459, 1344, 1289, 1241, 1177, 1070, 1027; 1H NMR (400 MHz, DMSO-d6) d 7.89 (1H, s), 7.49 (2H, d, J ¼ 8.4 Hz), 6.87 (2H, d, J ¼ 8.4 Hz), 6.45 (1H, d, J ¼ 2.0 Hz), 6.39 (1H, d, J ¼ 2.0 Hz), 3.87 (3H, s), 3.75 (3H, s), 3.73 (3H, s), 3.72 (3H, s); 13C NMR (100 MHz, DMSO-d6) d 174.6, 162.7, 162.6, 158.5, 144.6, 141.7, 130.3, 129.1, 121.9, 113.8, 112.4, 95.1, 91.2, 56.4, 56.1, 55.7, 41.5; LRMS (FAB) m/z 326.1 (M þ Hþ); HRMS (FAB) calcd for C19H20N O4, 326.1392; found: 326.1391 (M þ H)þ. 5.2.39. 5,7-dimethoxy-3-(4-methoxyphenyl)-1-ethyl-1H-quinolin4-one (10c) This compound was prepared from 10a using the same procedure as described for the preparation of 8b: Yield 88%; IR (neat, cm
1) 3284, 1641, 1562, 1515, 1449, 1362, 1159, 836; 1H NMR

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(400 MHz, DMSO-d6) d 7.82 (1H, s), 7.49 (2H, d, J ¼ 8.4 Hz), 6.89 (2H, d, J ¼ 8.4 Hz), 6.50 (1H, d, J ¼ 2.0 Hz), 6.45 (1H, d, J ¼ 2.0 Hz), 4.21 (2H, q, J ¼ 7.2 Hz), 3.91 (3H, s), 3.88 (3H, s), 3.78 (3H, s), 1.42 (3H, t); 13 C NMR (100 MHz, DMSO-d6) d 174.6, 162.8, 162.7, 158.5, 143.3, 140.7, 130.4, 129.1, 122.3, 113.7, 112.8, 94.9, 90.9, 56.4, 56.2, 48.3, 14.6; LRMS (FAB) m/z 340.1 (M þ Hþ); HRMS (FAB) calcd for C20H22N O4, 340.1549; found: 340.1550 (M þ H)þ.

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normalize the transfection efficiency, b-galactosidase plasmid was co-transfected. The luciferase activities were measured using luciferase assay system (Promega Corp., Madison, WI) and the bgalactosidase activities were measured as the absorbance at 410 nm by using an ELISA plate reader. Data are reported as relative luciferase activity divided by the b-galactosidase activity. 5.5. ER competitive binding affinity assays

5.2.40. 5,7-dimethoxy-3-(4-methoxyphenyl)-1-propyl-1Hquinolin-4-one (10d) This compound was prepared from 10a using the same procedure as described for the preparation of 8b: Yield 84%; IR (neat, cm
1) 2963, 2934, 1632, 1612, 1591, 1463, 1289, 1245, 1163, 1038, 834; 1H NMR (400 MHz, CDCl3) d 7.57 (2H, t, J ¼ 8.4 Hz), 7.44 (1H, s), 6.90 (2H, d, J ¼ 8.4 Hz), 6.34 (1H, d, J ¼ 2.0 Hz), 6.29 (1H, d, J ¼ 2.0 Hz), 3.97 (2H, q, J ¼ 7.2 Hz), 3.94 (3H, s), 3.90 (3H, s), 3.81 (3H, s), 1.89 (2H, tq, J ¼ 7.2 Hz), 1.00 (3H, t); 13C NMR (100 MHz, CDCl3) d 175.7, 163.2, 162.4, 158.5, 143.1, 139.7, 130.1, 128.2, 123.1, 113.4, 112.9, 93.9, 90.0, 56.2, 55.7, 55.3, 21.7, 11.2; LRMS (FAB) m/z 354.2 (M þ Hþ); HRMS (FAB) calcd for C21H24N O4, 354.1705; found: 354.1740 (M þ H)þ. 5.3. Molecular modeling 5.3.1. Minimization of molecules All the molecules for docking were sketched in the SYBYL-X and energy minimizations were performed using Tripos Force field and Gasteiger-Huckel charge with 100,000 iterations of conjugate gradient method with convergence criterion of 0.05 kcal/mol. After minimization is completed, all molecules are included in a database for docking analysis. 5.3.2. Protein preparation Crystal structures of genistein bound to ERa and ERb (PDB code 1X7R and 1X7J) were refined using the following protocol. All hydrogen was added to selected protein as random orientation and the charge was loaded to protein and ligands with MMFF94 and Gasteiger-Huckel, respectively. Sidechain amide was fixed and then staged minimization of biopolymer hydrogens and ligands was performed with 100 iterations of conjugate gradients method to a gradient of 0.5 kcal using MMFF94s Force field and charges. For next docking study, originally bound ligand was extracted from prepared protein. 5.3.3. Docking studies All molecular modeling calculations were carried out using the Surflex Dock interfaced with SYBYL-X version 2.0. In this automated docking program, the flexibility of the ligands is considered while the protein or biomolecule is considered as a rigid structure. The ligand is built in an incremental fashion, where each new fragment is added in all possible positions and conformations to a pre-placed base fragment inside the active site. The protomol was generated using the crystallized ligand with a threshold of 0.50 as default settings. All other parameters accepted the default settings. The 3D coordinates of the active site were taken from the X-ray crystal structures of the ERa and ERb (PDB code 1X7R and 1X7J) reported as complex with genistein. 5.4. ERE-luciferase reporter gene assay CV-1 cells were seeded in 48-well plate at a density of 1.5  105 cells/well. One day after seeding, the cells were cotransfected with 30 ng hERa (or hERb) and 100 ng pERE-luciferae plasmid in each well for 6 h, and further treated with vehicle and samples for 24 h before harvesting for the luciferase assay. To

The competitive ER binding assay was performed as previously described (Arcaro et al., 1999). Briefly, 6 nM of the recombinant human ER (rhER a, b Invitrogen Life Technology, Inc., CA, USA) was incubated with test compounds for 9 h at room temperature in the presence of 2.5 nM of [2,4,6,7-3H]-E2 (81.0 ci/mmol). Subsequently, 100 mL of 50% (v/v) hydroxyapatite slurry was added to the reaction mixture for 20 min at 4  C. Bound and free radioligand were separated by centrifugation at 12,000  g for 2 min, and the radioactivity of the supernatant was determined using a liquid scintillation counter (LS-6500, Beckman counter, CA, USA). The amount of the receptor-bound [3H]-E2 in the presence of the test compounds was presented relative to maximum receptor bound ligand (10-7 M E2). The data are expressed as the ratio of the receptor-bound [3H]-E2 in the presence of the compounds to the 0.1% DMSO used as a control. The IC50 values were determined from doseeresponse curves obtained from three separate experiments. 5.6. MTT assay MCF-7 cells were seeded in 96-well plate at a density of 1.5  103 cell/well for 24 h and followed by the treatment of 0.1 nM E2, 100 nM ICI and the indicated concentrations of samples. After 4 days, MTT solution (5 mg/mL in phosphate buffered saline) was added to each well and further incubated for 2 h. The absorbance of the formazan crystals dissolved in 100 mL of DMSO was measured at 540 nm using the microplate reader (VERSAmax Molecular Devices, CA, USA). Acknowledgments This work was supported by the National Research Foundation of Korea grant funded by the Korea government (Project No. 20110030074) and the SRC Research Center for Women's Diseases of Sookmyung Women's University (2011). Appendix A. Supplementary data Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.ejmech.2014.07.030. References [1] D.P. McDonnell, J.D. Norris, Science 296 (2002) 1642e1644. [2] J.F. Couse, J. Lindzey, K. Grandien, J.A. Gustafsson, K.S. Korach, Endocrinology 138 (1997) 4613e4621. [3] D.C. Leitman, S. Paruthiyil, O.I. Vivar, E.F. Saunier, C.B. Herber, I. Cohen, M. Tagliaferri, T.P. Speed, Curr. Opin. Pharmacol. 10 (2010) 629e636. [4] J.E. Rossouw, G.L. Anderson, R.L. Prentice, A.Z. LaCroix, C. Kooperberg, M.L. Stefanick, R.D. Jackson, S.A. Beresford, B.V. Howard, K.C. Johnson, J.M. Kotchen, J. Ockene, J. Am. Med. Assoc. 288 (2002) 321e333. [5] R.T. Chlebowski, S.L. Hendrix, R.D. Langer, M.L. Stefanick, M. Gass, D. Lane, R.J. Rodabough, M.A. Gilligan, M.G. Cyr, C.A. Thomson, J. Khandekar, H. Petrovitch, A. McTiernan, J. Am. Med. Assoc. 289 (2003) 3243e3253. [6] a) O.B. Wallace, T.I. Richardson, J.A. Dodge, Curr. Top. Med. Chem. 3 (2003) 1663e1682; b) A.D. Palkowitz, A.L. Glasebrook, K.J. Thrasher, K.L. Hauser, L.L. Short, D.L. Phillips, B.S. Muehl, M. Sato, P.K. Shetler, G.J. Cullinan, T.R. Pell, H.U. Bryant, J. Med. Chem. 40 (1997) 1407e1416. [7] a) Lancet 351 (1998) 1451e1467; b) B. Fisher, J.P. Costantino, D.L. Wickerham, C.K. Redmond, M. Kavanah,

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[8] [9]

[10] [11]

[12]

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